A $5 set of used golf clubs could be the deal of a lifetime for a New Mexico man.

When Larry Brooks bought a black Callaway bag attached to a pull cart from a thrift store, he had no idea that it would contain a gold medal he believes was awarded to 1940 Masters Tournament runner-up Lloyd Mangrum.

"I heard something rattling around," said Mr. Brooks, who lives in McIntosh, N.M. "I stood it back up, and I was shaking the bag out with golf balls, tees and stuff falling out. I could still hear something falling out."

The retired man found a black plastic sleeve with a medal in it.

The front of the medal has the words Augusta National Golf Club and shows a replica of the clubhouse. The back says Masters Tourna ment and has "Lloyd Mangrum," "runner-up" and "1940" engraved. The medal features the club's distinctive logo of the outline of the United States with a flagstick marking Augusta.

The medal is gold, Mr. Brooks said, and that's where the questions begin. Masters records indicate that the tournament runner-up received a silver medal beginning in 1951. The Masters winner has received a gold medal since the tournament's inception in 1934.

The World Golf Hall of Fame in St. Augustine, Fla., has a silver medal from 1935 runner-up Craig Wood on display. According to the World Golf Hall of Fame, the 1935 medal is on loan from a private collector and is the original medal issued to Wood.

Mr. Brooks has contacted numerous organizations and memorabilia dealers in an attempt to authenticate his medal. Most agree it is real, but they're not sure of its value.

Mr. Brooks talked with a representative from Augusta National, but the club wants to see it before determining its authenticity.

"In the golfing world, it's a pretty significant find," Mr. Brooks said. "To a collector that's a Masters buff, it's probably priceless."

Mangrum, a native of Trenton, Texas, who died in 1973, played in 20 Masters between 1940 and 1962. He was runner-up to Jimmy Demaret in 1940, and he tied for second in 1949. He shot a course-record 64 in the opening round in 1940, a score that wasn't equaled until Jack Nicklaus matched it in the third round of the 1965 Masters.

Mangrum served in World War II and was injured during the invasion of Normandy and at the Battle of the Bulge. According to his World Golf Hall of Fame profile, he received two Purple Hearts and four battle stars for his service.

Mr. Brooks, who describes himself as a recreational golfer and has never been to Augusta, isn't sure what he will do with the medal.

"He may have a family member who is still alive," he said. "To me it's a piece of history. But I'm having a ball with this thing."